An idea for large payload orbital delivery:
1. Adapt shuttle type vehicle to carry 100-ton payload.
2. Adapt main fuel tank to carry more fuel and correspondingly less oxidizer.
3. Synchronize launch with large ocean based pre-accelerator (see www.hypacc.com).
4. Loft scramjet powered drone-carrying remainder of required oxidiser.
5. Drop solid boosters in usual fashion.
6. Dock oxidizer drone with shuttle (Ok, very tricky but possible in very thin atmosphere)
7. Continue journey to orbit/ISS
8. Repeat several times.
9. Build space ship.
10. Go to Mars!
I have built some very small models of my original Hydro Pneumatic Accelerator (HYPACC) and some models that demonstrate a column of water will effectively drive a pump gun (Hydro Pump Accelerator. HYPACC 2). the aim being to reduce the engineering costs and eliminate the recoil issues of up-scaling the SHARP light gas gun.

are you speaking about a reusable vehicle or about an expendable vehicle?

If it is expendable then the question is which amount of investment in dollars is required because this amount up to now usually makes up more than 90% of the launch costs/flight costs.

If it is reusable the question still is the amount of investment but the question for the number of flights to be expected must be added. The larger that number the smaller the costs per launch/flight - but the larger the capacity (100 mT here) in relation to the total weight of all payloads to be expected the smaller the number of flights to be expected and the larger the costs per launch/flight until the investment is depreciated.

The idea

Quote:

Dock oxidizer drone with shuttle (Ok, very tricky but possible in very thin atmosphere)

I long ago started a thread about in the Technology section in a version abit different - the title is "Combining" if I remember correct. It might include informations of meaning for what you say.

I guess the vehicle would not be reusable as once linked it would travel with the shuttle on its main long burn to near orbital velocity. In an ideal world the scramjet component of the drone would jettison immediately after docking and could be reused. The oxidizer tank would burn up after use along with the main shuttle tank.

There seems to be a great deal at stake for the next logical step in orbital access. Hybrid jet/scramjet/rocket engines would do all of this far easier than using a pump gun or maglev etc. I believe the issue is a strategic one. If such an engine were developed (my guess is it has been for a while) the implications of such technology becoming available to the emerging powers of the world would be a military strategistâ€™s nightmare. Once the existence of hardware becomes public knowledge it is just a matter of time before itâ€™s secrets follow suit.

A very large oceanic pump gun, such as HYPACC 2, would have little or no strategic value. It could be used for the first stage in sending unmanned (scramjet/rocket) vehicles all the way to the ISS but limited to tough payloads that can withstand the initial g-forces of going from 0 to 5x the speed of sound in the length of the barrel. If the oxidiser accounts for a large part of the weight of a conventional rocket why not blast it out of a big gun, utilise the O2 it passes on the way and get it to join the soft payload and live crew just as the shuttle is running out of O2? All of this without creating a vehicle that can fly halfway around the world in half an hour, drop something nasty and be home again in time for tea!

Politics created the shuttle. (Weâ€™ve got a spaceship Youâ€™ve just got a capsule Ha HA)
Politics will dictate the next step and I hope itâ€™s forward.

6. Dock oxidizer drone with shuttle (Ok, very tricky but possible in very thin atmosphere)

Tricky is an understatement! You only have maybe 1 or 2 minutes at the most to dock and start transferring oxidizer; and you get one try before the booster just falls and crashes. It takes the shuttle or Soyuz half an hour or something like that to get all lined up and docked to the space station, not counting all kinds of leak checks and stuff before the hatches can open. And they have as long as they want to try again and again if there is a problem.

It seems the idea falls flat at this point however the link up would have to be automated and occur with both drone and shuttle main engines cut in a time frame of just a few seconds. The increasing power and speed of computers has effectively placed them in a highly compressed time frame when compared to our own. The new Euro fighter already employs highly sophisticated computing to keep it in the air, making thousands of decisions and adjustments every second. I accept 'tricky' is a stupid understatment, I was just flaging it as the weakest aspect of the idea.

[quote]I long ago started a thread about in the Technology section in a version abit different - the title is "Combining"

Ekkehard ,
I had a look at the above thread and the concept is similar. I think the advantage with this combination is the fuel saving from the pump-gun and the scram engine and therfore possibly worth the additional trouble and complication.

what do you think to be the required amount of investment into hardware? At expendability this investment needs to be repeated each launch/flight and in the case of reusable vehicles like SpaceX's Falcons and t/Space's CXV it makes a difference of lots of millions.

Hello Ekkehard,
I cannot give any costs for a working model, as it remains a sketch concept. The design of HYPACC 2 is centred on keeping the engineering costs to a minimum however the development would not be cheap. The object of this thread was to get some feedback on the idea of combining manned soft payloads with HYPACC 2. According to one rocket scientist who posted a reply on the Nasa forum (same initial thread) said it would be impossible to link two vehicles but as I am not ignoring any laws of physics I will only concede that rocket scientists are not currently capable of such a manoeuvre.
For now I am going to concentrate on the original concept of using HYPACC 2 as a pre-accelerator for scramjet drones delivering tough payloads to the ISS. Scramjet technology seems to be moving forward and a cheap, compact launch system that precludes the need for a jet/scramjet hybrid may be a practical step forward. The issue of reusability of such drones may be more a case of recycle-ability and using the material in orbit for other purposes.